(CNSNews.com) – House Judiciary Committee Chairman John Conyers (D-Mich.), echoing others who testified before a subcommittee on Thursday, said both the George W. Bush and Barack Obama administrations represent an “imperial presidency.” Obama, Conyers said, has broken his promises to shut down Guantanamo, end military operations abroad, and has continued to expand the power of the executive branch.

“The power of what has begun to be termed the imperial presidency grows, and the ability of our Democratic institutions, especially the federal legislative branch – us – to constrain it seems more uncertain,” Conyers said in his opening remarks at a hearing of the House Judiciary Committee’s Subcommittee on the Constitution, Civil Rights, and Civil Liberties.

Conyers said the Obama administration continues to use executive privilege as strategy for national security at the cost of Americans’ civil liberties.

“The repeated invocation of the state secrets privilege, which has gone on in recent years, including this administration, to an incredible new height,” Conyers said.

Conyers said the Obama administration has “shut down complaints, investigations and lawsuits challenging executive branch action, such as illegal domestic surveillance, torture and rendition.”

Laura Murphy, director of the American Civil Liberties Union’s (ACLU) Washington legislative office, testified that the Obama administration has continued the expansion of executive branch power.

“From the Bush administration’s use of warrantless wiretapping to the Obama administration’s targeting killing program, the power claimed by the executive branch has grown exponentially over the last 10 years,” Murphy said.

“To realign our system of checks and balances, Congress must continue to forcefully reassert its oversight duty to ensure that the executive branch does not continue to expand its powers without regard for Americans’ basic liberties,” she added.

An ACLU press release distributed to reporters at the hearing said Murphy’s testimony was about how “the executive branch of the U.S. government has obtained dangerously broad powers.”

Murphy cited in her testimony that the Patriot Act, warrantless wiretapping, and the “misuse of the state secrets privilege” have taken away from the checks and balances needed to reign in the executive branch’s power.

Murphy argued that some issues facing the next Congress could put national security above civil liberties, including the proposed changes to the Use of Military Force to address the terrorist enemy and the use of the Internet to track terrorist activities.

Conyers also said that Obama’s accomplishments have been “undermined by disappointments.”

“The 44th president started his term on a positive note, when he banned torture and the use of secret prisons or ‘black sites,’ ordered the Guantanamo detention camp closed, and revoked and released the gravely flawed Office of Legal Counsel torture memos,” Conyers said. “But the progress has not been nearly enough, and these positives steps are in many ways undermined by other disappointments.

“For instance, the [Obama] administration has failed to adequately investigate or prosecute apparent national security crimes, such as torture and waterboarding, and does not appear to have even investigated those who approved or ordered these crimes in the first place,” Conyers said.

“While we in Congress deserve our fair share of the blame for this failure, it is, nevertheless, a failure,” he said.

Conyers also charged that Obama’s military drone program in Pakistan had killed innocent people.

“Public reports describe extensive use of drones, not only in the battlefield but where villages and huge civilian populations can be destroyed, which amounts to an incredible extension of war in a new sense, unlike any that we’ve experienced before,” Conyers said.

Conyers was the only member on the subcommittee to hear the six panelists’ testimony during the almost three-hour hearing.

Ranking member Rep. James Sensenbrenner (R-Wis.) only stayed long enough to give an opening statement.

Sensenbrenner said Americans are still waiting for the “hope and change” promised by Obama and the Democrats and that when the subcommittee is under “new management” in January it will work more effectively.

Others testifying for the “national security and civil rights” hearing were Bruce Fein, associate deputy attorney general in the Reagan administration; former U.S. Ambassador to the United Nations Thomas Pickering; Michael Lewis, a law professor at Ohio Northern University Pettit School of Law; trial attorney Jamil Jaffer; and Jeremy Scahill, a reporter with the liberal news journal The Nation.